export class DataTableSortDemo implements OnInit {

    cars1: Car[];

    cars2: Car[];

    constructor(private carService: CarService) { }

    ngOnInit() {
        this.carService.getCarsSmall().then(cars => this.cars1 = cars);
        this.carService.getCarsSmall().then(cars => this.cars2 = cars);
    }

    changeSort(event) {
        if (!event.order) {
          this.sortF = 'year';
        } else {
          this.sortF = event.field;
        }
    }
}

<h3 class="first">Single Column</h3>
<p-dataTable [value]="cars1" [sortField]="sortF" [sortOrder]="sortO" (onSort)="changeSort($event)">
    <p-column field="vin" header="Vin" [sortable]="true"></p-column>
    <p-column field="year" header="Year" [sortable]="true"></p-column>
    <p-column field="brand" header="Brand" [sortable]="true"></p-column>
    <p-column field="color" header="Color" [sortable]="true"></p-column>
    <p-footer>
      <button type="button" label="Sort by Year" (click)="changeSort($event)" pButton></button>
    </p-footer>
</p-dataTable>

<h3>Multiple Columns</h3>
<p-dataTable [value]="cars2" sortMode="multiple">
    <p-column field="vin" header="Vin" [sortable]="true"></p-column>
    <p-column field="year" header="Year" [sortable]="true"></p-column>
    <p-column field="brand" header="Brand" [sortable]="true"></p-column>
    <p-column field="color" header="Color" [sortable]="true"></p-column>
</p-dataTable>